If you want to keep the data in the table as it is and remove the area code in a select, do this:
SELECT REPLACE(STUFF(phonenumber,1,CHARINDEX(')',phonenumber),''),'-','') FROM dbo.customerIf you want to permanently change the table by updating it to remove the area code, do this:UPDATE dbo.customer SET
phonenumber = REPLACE(STUFF(phonenumber,1,CHARINDEX(')',phonenumber),''),'-','');